An increase in activated partial thromboplastin time, i.e., prolongation, suggests a coagulation factor deficiency. The most fundamental treatment is, first of all, to see what causes it, and if it is hemophilia to supplement coagulation factors, hemophilia A to supplement factor VIII, hemophilia B to supplement factor IX. Our clinical supplementation is often fresh frozen plasma, cold precipitation, and prothrombin complex. Fresh frozen plasma and cold precipitation will contain factor VIII, and prothrombin complex can supplement factor IX. If we exclude coagulation factor deficiency other than hemophilia, then we will see the situation. If the APTT is prolonged, it is usually better to transfuse fresh frozen plasma and cold precipitate. The prolongation of activated partial thromboplastin time suggests that we have internal coagulation factor deficiency, then we should see what causes it, and after finding out the cause, we should first treat the original disease, and if the patient has obvious bleeding symptoms, immediately supplement the coagulation factors. There are many ways to supplement coagulation factors, including fresh frozen plasma transfusion, cold precipitation, prothrombin complex, and also factor VIII deficiency, such as factor VIII injection, which can be directly supplemented.